CA1
Chr 8carbonic anhydrase 1
Also known as: CA-I, CAB, Car1, HEL-S-11
Carbonic anhydrase 1 is a cytosolic zinc metalloenzyme that catalyzes the reversible hydration of carbon dioxide, participating in acid-base balance, respiration, and formation of cerebrospinal fluid. Mutations cause carbonic anhydrase I deficiency, which follows autosomal recessive inheritance and typically presents with mild hemolytic anemia and distal renal tubular acidosis. The gene shows tolerance to loss-of-function variants (high LOEUF score), consistent with the generally mild clinical phenotype.
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Highly tolerant — LoF variants common in population
Tolerant to missense variation
The highest-scoring mechanism for this gene is dominant-negative.
Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.
Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.
ClinVar Variant Classifications
80 submitted variants in ClinVar
Classification Summary
Curated Variants Distribution
Classified variants from ClinVar · 5 ACMG categories
| Classification | LoF | Missense + Inframe | Non-coding | Synonymous | Total |
|---|---|---|---|---|---|
Pathogenic | 0 | 2 | 30 | 0 | 32 |
Likely Pathogenic | 0 | 0 | 0 | 0 | 0 |
VUS | 1 | 29 | 8 | 0 | 38 |
Likely Benign | 0 | 1 | 1 | 0 | 2 |
Benign | 0 | 3 | 0 | 1 | 4 |
| Total | 1 | 35 | 39 | 1 | 76 |
LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly
View in ClinVar →Protein Context — Lollipop Plot
CA1 · protein map & ClinVar variants
Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.
3D Protein StructureAlphaFold
External Resources
Links to major genomics databases and tools
Clinical Trials
Active and recruiting trials from ClinicalTrials.gov
External Resources
Links to major genomics databases and tools